Screw-type well packer



2 Sheets-Sheet 1 Filed June 29, 192;

mvis; 1928;

' 1,690,383 H. THOMSON SCREW TYPE WELL PAGKER I Filed June 29, 1925 2Sheets-Sheet 2 as1,-dQ@f%WQ I mm ' and the strainer, or a Patented Nov.6, 1928.

my rizousolv, or \HOUSTON, 'irnxas, A muracruame COMPANY, or nousrSSIGNOR TO STANCLIFFE WELL SCREEN & N, TEXAS, A CORPORATION OF TEXAS.

SCREW-TYPE WELL PACKER.

My invention relates to well packers and pertains particularly to canvaspackers adapted to be compressed longitudinally and thus expandedlaterally to close the space within the well casing at the upper end ofthe well strainer.

' It is an object of the invention to provide a packer which will expanduniformly and serve toti htly fill the space to be packed off thereby. tis a further object that the device be adapted to be again contracted,after expansion, so that it may be withdrawn from or relocated in thewell when desired. The

device is further adaptedto be inserted or withdrawn from the wellwithout the use of a ial setting tool. 1

urther objects of the invention will appear from the specification whichfollows.

In the drawing, a preferred form of the invention is disclosed. Figs. 1and 2 are longitudinal views partly in central section of the invention,.Fig. 1 illustrating the upper end and Fig. 2 the lower end of theassembled device. Fig. 3is a transverse section on the plane 3 3 of'Fig. 1. Fig. 4 is a side elevation of my packer placed in the casing.Fig.

5 is a similar elevation showing the packer in expanded position. .Fig.6 is a transverse sectlon on the lane 6-6. of Fig. 2, the canvas stripsbeing s own somewhat diagrammatically. Like numerals of referencedesignate like parts in all the views.

My packer is particularly adapted to close the space around the .upperend of the strainer within the lower end of the casing;

it is employed most commonly in finishing.

the well to determine whether the same is a producing well or not. It isdesirable that the packer be capable of being placed and I set to testthe well, but if the test is found to be unsuccessful, it is desirablethat the packer be capable of bein withdrawn, for further development oft e well. The packer is adapted to closethe ace between the casing out awell tubing, if so desired.

. In can-yin out the invention, I secure at the upper-en of the strainer1 a tubular mandrel 2, said mandrel being secured to the.

strainer by means of a coupling or collar 3.

a pncation filed June 29, 1925. Serial No. 40,425.

The mandrel is threaded with a coarse thread 4 along the upper halfthereof to provide engagement for a nipple 5.

The said nipple5 comprises a pipe or 001- lar, the ends of which arethickened inwardly and threaded to be screwed down over the mandrelallowing the mandrel to project upwardly therein. At the upper end ofthe nipple a short connecting pipe 6 is secured and it is contemplatedthat the threaded connection will be formed by a so-called lefthandthread, that is, one whereby the connection is made between the section6 and the nipple by screwing downwardly with a counter clockwise turn ofthe pipe section. This connection makes it possible to disengage theconnecting pipe 6 from the nipple by a right-hand or clock-wise rotationof the drill stemto which the packer may be secured. The connectionbetween the section 6 and the nipple may be reinforced, if desired, by apin 7 of frangible material which is extended radially through the upperend of the nipple and the connecting pipe.

The lower end of the nipple 5 isundercut to provide an overhanging skirt8 spaced away from the outer threaded face of the mandrel; An innergroove 9 is formed in said skirt to accommodate a series of balls 10forming a roller bearing between the said skirt and the upper reducedportionll of a slip 12. Said slip is also grooved to register with thegroove in said skirt, thusformin a ball race in which the balls mayroll. T is arrangement provides a swiveled connection between the slip12 and the nipple; it permits the rotation of the nipple upon the slip,allowing the slip to remain non-rotatable upon the mandrel while thenipple is being screwed downwardly; i

The slip 12 fits loosely over the threaded end of the Imandrel and istapered downwardly at 13 for a suitable distance -to assist in theexpansion in the packer, as will be presentl described. p

The s ip has secured at its upper end adja cent the swiveled connectiona packer comprising a series of longitudinal strips of flexiblemateriall l which will, under ordinary circumstances, be canvas or thelike, but may thus forcing it be of any flexible and compressiblematerial. The strips are secured in overlapping arrangement, as shown inFig. 6. The upper ends are engaged'within an undercut oove 15 formed bythe upper end of the slip, the canvas strips being retained therein byrolling or otherwise forcing the outer wall of the groove inwardlyagainst the packing to clamp it securely in pos'tion. This forms asecure hold upon the acking material and interferes in no way wit theoperation of the device.

The lower ends ofthe packing strips 14 are secured within a groove 16formed by undercutting the upper end of the collar 3 so that it willoverlap the lower ends of the said packing stri s; it is then bentinwardly to clamp the ac 'ng strips in position. intermediate band, orhoop 17, may be secured about the packing strips at a point adjacent thelower end of the slip 13, if desired, and such band is shown in thedrawing. This band assists in holding the strips in contracted positionwhile the device is moved to or from its position 'at the bottom of thewell.

In assembling the device, the strips 14:, constitutin the packer, aresecured to the slip 13 as escribed. The slip is then secured upon thelower end of the nipple 8. Thisis done by fixing the slip in the lowerend of the nipple and then placing the balls in position within thegroove 9. This is done by providin an opening 18 in the outer wall ofthe skirt 8 and inserting the balls through said opening one by oneuntil the groove is entirely filled. The '0 ening may their .be stoppedby a threade plug, or by solder, if desired. The mandrel is then screwedwith- "in the lower end of the nipple and the packing strips secured attheir lower end within the collar 3.

When the device is inserted. into the well,-

the strainer 1,. and perhaps a pipe section thereon, are secured at thelower end of the coupling 3, and the device is lowered downwardly withinthe casing 19. When the lower end of the strainer engages the bottom ofthe well, the packer may then be expanded by compressing itlongitudinally, outwardly against the casing. In Fig. 4 the packer isshown in extended or unexpanded position. The rotation of the drillstem, which is employed to operate the device, will cause the rotationof the nipple 5 screwing it downwardly over the mandrel which remainsstatioiiary in the well. The slip 13 serves to' assist in maintainingthe packer against rotation with the nipple, the swivel engagementallowing the stationary position of the packer. As the ni ple 5 is moveddownwardly on the man rel, the packer will be compressed longitudinally,and in Fig. 5 the packer is shown partially expanded, and it will benoted that the strips An upon the mandrel are compressed uniformlydownward without twisting1 upon the mandrel. The lower portion of t epacking strips will be expanded first, due to the presence of the slip13 which moves downwardly with the upper end of the packing strips so asto first expand the lower end; this avoids the enga upper end of thepacker first with the casing which would prevent complete expansion ofthe lower end thereof. The slip also serves to assist in forcing thepacking strips outwardly a ainst the casing. When fully expanded, t epacking strips will form a uniformly tight closure between the mandreland the well casing in an obvious manner.

When the packer is fully set, the resistance to further downwardscrewing of the nipple will become so great that the connecting pipesection 6 will begin to exert a strain upon the threaded connectionbetween the same and the nipple breaking the pin 7 and rotating the pipeconnection to un-v screw it from the packer. The drill stem and the pipesection may then be withdrawn, if desired. I

If it becomes desirable to remove or change the packer, the drill stemmay be again inserted downwardly and rotated in a left-hand direction toengage the section 6 with the upper end of the nipple. The rotationthereafter with the nipple in the opposite direction will screw itupwardly along the mandrel contracting the packing material andreleasing the packer from the casing so that it ma be withdrawn. Aradial pin 20 is provide between the threads at the upper' end ,of themandrel to limit the upward screwing ing. This avoids the unevenexpansion which is sometimes obtained b spirall arranged packingmaterial whic is liab e to stick to the mandrel at some points beforethe device is fully expanded. The use of the slip also serves to assistin expandin the packer uniformly from the lower en upwardly until thewhole packer has been uniformly expanded. The swivel engagement betweenthe slip and the nipple is peculiarly efficient for this urpose andforms an important part of t e invention. The further objects andadvahta es of the device will be obvious to those sk ed in the artwithout further description.

What I claim as new and desire to protect by Letters Patent is:

In a packer for wells, a tubular mandrel, a

ement of the collar connecting with said mandrel, said mandrel beingcoarsely threaded at its upper end, a nipple havin threaded engagementwith the upper end 0 said mandrel, a downwardly tapered slip suspendedon and having rotative engagement with the lower end of saidnippleyoutside said mandrel, a canvas packer on said slip and mandreland secured at its lower end to said-collar, and means to connect saidnipple to atubular drill stem.

In testimony whereof I hereunto aflix my signature.

HARRY THOMSON.

